Pushbutton switch with spring loaded slider



Jan. 17, 1961 s A. WOODWARD ETAL 2,968,704

PUSHBUTTON SWITCH WITH SPRING LOADED SLIDER Filed June 2'7, 1958 FIG. I.

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b3 MAJ of @A 43 The? Arrovneg United States Patent PUSHBUTTON SWITCHWITH SPRING LOADED SLIDER Stewart A. Woodward, Stratford, and Sam M.Golden, Fairfield, Conn., assignors to General Electric Company, acorporation of New York Filed June 27, 1958, Ser. No. 744,979

3 Claims. (Cl. 20018) The present invention relates to an electricalswitch and particularly a multiple pushbutton switch having a series ofmanually operated pushbuttons which are individually operated to provideselective circuits for a variable load such as electric ranges, room andcommercial air conditioners, washing machines, electric broilers andwindow fans. The basic patent for such multiple pushbutton switches isthe Andrews Patent No. 2,431,904, which is assigned to the same assigneeas is the present invention.

Many desirable improvements have been added to pushbutton switches overthe years. For example: A detent action can be provided for each of thebuttons so that a given circuit cannot be opened and then immediatelyreclosed, which would be a serious fault if the switch were installedwith air conditioning equipment, as explained in the Hutt Patent No.2,723,317. Another improvement would include a momentary contact actionfor one of the pushbuttons when the switch is used for the control ofsolenoids or for starting fluorescent lamps. A third improvement wouldbe the feature whereby the OFF button of the switch is always returnedto its outermost position immediately after it is depressed andreleased. When the switches are used on electric ranges, the buttonswill all be in the outermost position when the range is not being used,thus improving the over-all appearance of the appliance.

The principal object of the invention is to provide a pushbutton switchwith a spring loaded slider that may perform one of several functions;namely, the function of a detent slider, a button-return slider or amomentary contact slider.

A further object of this invention is to provide a multiple pushbuttonswitch with an additional elongated slider that is spring loaded at oneend to give the switch one of several variations such as a detentaction, a buttonreturn action or a momentary contact action.

The present invention represents an addition to the standard models ofpushbutton switches. The advantages of this invention can be obtained bymerely adding another slider that is spring loaded at one end so thatthis slider will always return to its original position once manualpressure is released from all of the buttons. Different types of actioncan be obtained from this additional slider by adopting one of severaltypes of inclined surfaces on the slider that either lock a depressedbutton in the down position or return a depressed button to itsoutermost position when manual pressure is released. Our invention willbe better understood from the following description taken in connectionwith the accompanying drawing and its scope will be pointed out in theappended claims.

Figure 1 is a front view of a six position pushbutton switch embodyingthe present invention.

Figure 2 is a bottom plan view of the switch of Figure 1 with the bottomcover removed to show the inner workings of the switch mechanism andparticularly the coiled spring at the right end of the housing bearingagainst the end of a particular slider in a series of five elongatedsliders assembled in the switch.

Figure 3 is a layout view of the five sliders of the switch shown inFigure 2 with particular emphasis given to the second slider from thetop which is the additional slider that provides a button-return action.

Figure 4 is a similar layout view showing a group of four sliders wherethe second slider from the top is the additional slider that provides adetent action for all of the buttons of the switch.

Figure 5 is a showing of a second modification of the additional springloaded slider and it is closely related to Figure 3 providing for thereturn of two buttons upon the release of manual pressure.

Figure 6 is a third modification of the spring loaded slider where oneedge of the slider is undercut to provide cam surfaces for cooperationwith the movable contacts of the switch, so that the right-hand endbutton has momentary contact action.

Figure 7 is a diagrammatic showing of the action of a flat column springthat assumes an S-shape and is a substitute for the coiled spring ofFigure 2.

Referring in detail to the drawing and in particular to Figure 1, 10represents a hollow switch housing formed by a recessed base member 11of suitable molded insulating material and a thin bottom cover plate(not shown) as is well-known in this art. The switch shown in Figure 1happens to be a six position switch with six push rods 12 that extendthrough suitable openings in the top wall of the base 11 for cooperationwith the elongated sliders shown in the layout views of Figures 3-6. Theterminals of the contacts of the switch extend downwardly from thebottom of the base 11. The line terminals 13, 14 and 15 are disposed atone side of the base while the load terminals 16, 17, 18 and 19 arearranged on the opposite side of the base, as will be understood from astudy of the bottom plan view of Figure 2. Cantilever spring blades 20,which serve as the movable contacts of the switch, are fixed at one endto one of the load terminals 16-19, while the opposite end of each bladeis capable of movement toward and away from the fixed contacts of lineterminals 13-15.

The central portion 25 of the base 11 that extends longitudinallythereof provides a relatively deep recess 26 for the reception of astack 27 of elongated sliders of insulating material that are acted uponby the push rods 12 and are shifted to control the positions of themovable contacts 20 of the switch. A better understanding of thesesliders 27 may be had by referring to the layout view of Figure 3wherein the five sliders that make up the stack 27 are shown in detail.For identification purposes, these sliders are numbered 28-32. At theoutset it should be recognized that sliders 28 and 30-32 are standardsliders and that this invention relates to the additional slider 29 thatis spring loaded at one end by means of spring 33 shown at the rightend. It should also be understood that all of the sliders illustrated inthe drawing are positioned bottom-side-up for purposes of illustration.Looking at slider 28, its uppermost edge 34 is undercut to form camsurfaces 35 which are adaptedto engage the central portion of themovable contact blades 20 of the switch so as to open or close thevarious circuits through the blades. The lowermost edge 36 of the slider28 is provided with a series of inclined surfaces 37 which are engagedby the innermost ends of the push rods 12 for shifting the slider backand forth in the recess 26 of the switch base 11. Comparing are engagedby the push rods 12. While we have chosen to illustrate the inclinedsurfaces 37 as portions of open notches in one edge of the slider, itwill be understood that they also could be formed by stamping triangularholes in the sliders. Likewise, the inclined surfaces could be on thesame edge of the sliders that contains the cam surfaces for actuatingthe blades.

Particular attention will now be given to the additional slider 29 thatis spring loaded at the right end to retain the slider in a normal ororiginal position toward the left-hand side of the base 11. Theuppermost edge 39 of the slider is undercut as at 40, but no camsurfaces are included so that this slider will not engage any of themovable contact blades 20. Furthermore, the lowermost edge 41 of theslider 29 is notched but five of the notches are merely clearancenotches 42 of generally square shape which provide no interference withthe innermost ends of the push rods 12. However, the notch at the rightend of the slider has an inclined surface 43 so that when the relatedpush rod is depressed, it will shift the slider 29 to the right againstthe spring 33. It should be understood that the depression of thisrighthand push rod or button has not only shifted slider 29 but alsosliders 23 and 3t) and in so doing, the cam surfaces 35 will operatecertain of the contact blades 20. When manual pressure is released fromthat push rod, the compression spring 33 will expand and return theslider 29 to its original or normal position, thereby returning the pushrod to its outermost position. Hence, this additional slider 29 may beclassified as a button-return slider.

Figure 4 shows a first modification of the additional slider 29 ofFigure 3. This additional slider of Figure 4 is slider 49, and there arethree standard sliders 48, 50 and 51. As in the sliders of Figure 3,each of the standard sliders have cam surfaces 35 on their uppermostedge and inclined surfaces 37 on the lowermost edge. Again theadditional slider 49 has a compression spring 33 normally biasing theslider to the extreme left position. The uppermost edge 52 of the slideris deeply undercut so that no cam surfaces are provided that might actupon the contact blades 2%. The lowermost edge 53 of the slider 49 isprovided with a series of notches each with a doubly inclined latchingportion 54 for each push rod 12 of a button. Attention is directed tothe fact that the switch of Figure 4 would have only five push rodsrather than the six used in Figure l of the first modification.Accordingly, when a push rod is depressed, its innermost end will engagean outer inclined section of the latching portion 54 and force theslider to move against the action of the spring 33. After the push rodpasses the center of its inward movement, an inner reverse inclination55 of the latching portion will cause the slider to move behind the pushrod in the manner of a latch and temporarily lock the push rod in thedown position. This additional slider 49 may be classified as a detentslider in that it increases the resistance to the changing of thepositions of the push rods. For example: With one push rod in thedepressed position, pressure exerted against another button will causeit to move inwardly of the switch housing forcing the slider 49 againstthe spring 33. As the slider 49 moves, it will likewise unlatch thepush. rod in the down position. enabling it to move outwardly.

The second modification of this invention is illustrated in Figure 5,showing merely the additional slider 59 that is spring loaded at itsright end by the compression spring 33. This slider is closely relatedto slider 29 of Figure 3 in that it is a button-return slider. Itdiffers from slider 29 in that it has two inclined surfaces 43 forreturning two buttons once manual pressure is released.

Figure 6 is a third modification of the additional slider and it isidentified as 69. The same compression spring 33 bears against the rightend of the slider and normally biases the slider to the extreme leftposition.

This slider 69 is also similar to slider 29 of the first modification inthat it has a single inclined surface 43. Slider 69 differs from slider29 in that it includes cam surfaces 35 adjacent the uppermost edge ofthe slider for cooperation with the movable contact blades 20. Thisarrangement classifies this slider 69 as a momentary contact sliderbecause the extreme right-hand button is not only returned to itsoriginal position when manual pressure is released, but the slideractuates one or more circuits through the switch for controllingfluorescent lamps or solenoids and the like.

Having described above our invention of a novel slider construction fora multiple pushbutton switch, it will be readily apparent to thoseskilled in this art that this invention is both simple in design andmanufacture as well as versatile in application for incorporation instandard pushbutton switches. The several modifications of additionalsliders disclosed herein are interchangeable so that the demands of thecustomer may be satisfied by incorporating a small change in ourstandard production switch with little or no increase in cost. While wehave chosen as the preferred embodiment a coil spring acting against theend of the additional slider, a similar result would be obtained byusing one or more flat column springs 70 which are bowed by compressingtheir ends within the housing to form an asymetrical curved S-shape whenheld in the base against the slider, as shown in Fig. 7. Hence, when theadditional slider is compressed the S-shape of the spring will provide abiasing force against it, it being under stood that the slider bearsagainst the spring at a point offset from the center of the spring.

Modifications of this invention will occur to those skilled in this artand it is to be understood, therefore, that this invention is notlimited to the particular em bodiments disclosed but that it is intendedto cover all modifications within the true spirit and scope of theinvention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. In a multiple pushbutton switch comprising a housing, a plurality ofelongated longitudinally extending sliders assembled in the housing inside-by-side relation for sliding movement therein, one edge of severalof the sliders being undercut to form cam surfaces, a plurality ofmovable contact blades engageable with the cam surfaces of the sliders,each blade being fixed at one end to the housing and free to move at itsopposite end to make and break contact with a fixed contact of theswitch, a plurality of manually depressible pushbuttons into saidhousing through a wall thereof, each of said pushbuttons having anoutermost normal position and a depressed actuating position, eachslider having inclined surfaces which cooperate with at least one ofsaid pushbuttons, the inclined surfaces being arranged on the differentsliders so that only one button may be fully depressed at one time; theimprovement comprising a spring bearing against the end of at least oneadditional slider, and an actuating recess fromed in said one slider andarranged to cooperate with at least one of said pushbuttons, said springbraced against an internal end wall of the housing so that thedepression of said one pushbutton will cause the cooperation of saidpushbutton with said actuating recess to move said slider against thespring, said recess including on one side thereof an inclined edgeextending generally outwardly toward said one of said pushbuttons andtoward said end wall of said housing, a curved inner edge continuousfrom said inclined edge, and a vertical edge continuous from said curvedinner edge and disposed on the other side of said recess, said inclinededge cooperating with said one pushbutton upon the depression thereof tomove said slider against the force of said spring, said same inclinededge cooperating with said one pushbutton when manual pressure isreleased therefrom to return said one slider to its original position inresponse to the force of said spring thereby to return said pushbuttonto its outer normal position.

2, in a multiple pushbutton switch comprising a housing, a plurality ofelongated longitudinally extending sliders assembled in the housing inside-byside relation for sliding movement therein, one edge of severalof the sliders being undercut to form cam surfaces, a plurality ofmovable contact blades engageable with the cam surfaces of the sliders,each blade being fixed at one end to the housing and free to move at itsopposite end to make and break contact with a fixed contact of theswitch, a plurality of manually depressible pushbuttons extending intosaid housing through a wall thereof, each of said pushbuttons having anoutermost normal position and a depressed actuating position, eachslider having inclined surfaces which cooperate with at least one ofsaid pusnbuttons, the inclined surfaces being arranged on the differentsliders so that only one button may be fully depressed at any one time;the improvement comprising a coiled compression spring bearing againstthe end of at least one additonal elongated slider, said spring biasedslider being arrangeable to provide pushbutton returning force ormomentary contact actuation in said switch, and an actuating recessformed in said one slider and arranged to cooperate with at least one ofsaid pushbuttons, said spring braced against an internal end wall of thehousing so that the depression of said one pushbutton will cause thecooperation of said pushbutton with said actuating recess to move saidslider against the spring, said recess including on one side thereof aninclined edge extending generally outwardly toward said one of saidpushbuttons and toward said end wall of said housing, a curved inneredge continuous from said inclined edge, and a vertical edge continuousfrom said curved inner edge and disposed on the other side of saidrecess, said inclined edge coopcrating with said one pushbutton upon thedepression thereof to move said slider against the force of said spring,said same inclined edge cooperating with said one pushbutton when manualpressure is released therefrom to return said one slider to its originalposition in response to the force of said spring thereby to return saidpushbutton to its outer normal position.

3. In a multiple pushbutton switch comprising a housing, a plurality ofelongated longitudinally extending sliders assembled in the housing inside-by-side relation for sliding movement therein, one edge of severalof the sliders being undercut to form cam surfaces, a plurality ofmovable contact blades engageable with the cam surfaces of the sliders,each blade being fixed at one end to the housing and free to move at itsopposite end to make and break contact with a fixed contact of theswitch, a plurality of manually depressible pushbuttons extending intosaid housing through a Wall thereof, each of said pushbuttons having anoutermost normal position and a depressed actuating position, eachslider having inclined surfaces which cooperate with at least one ofsaid pushbuttons, the inclined surfaces being arranged on the differentsliders so that only one button may be fully depressed at any one time;the improvement comprising a flat column spring positioned transverselyadjacent an internal end wall of the housing, said spring being bowedbetween opposite side Walls of said housing to assume an asymmetricalS-shape, a bowed section of said spring bearing against the end of atleast one additional slider, and an actuating recess formed in said oneslider and arranged to cooperate with at least one of said pushbuttons,said spring running in compression between the side walls of saidhousing so that the depression of said one pushbutton will cause thecooperation of said pushbutton with said actuating recess to move saidslider against the force of the spring, said recess including on oneside thereof an inclined edge extending generally outwardly toward saidone of said pushbuttons and toward said end wall of said housing, acurved inner edge continuous from said inclined edge, and a verticaledge continuous from said curved inner edge and disposed on the otherside of said recess, said inclined edge cooperating with said onepushbutton upon the depression thereof to move said slider against theforce of said spring, said same inclined edge cooperating with said onepushbutton when manual pressure is released therefrom to return saidoneslider to its original position in response to the force of saidspring thereby to return said pushbutton to its outer normal position.

References Cited in the file of this patent UNITED STATES PATENTS2,213,845 Mastney Sept. 3, 1940 2,431,904 Andrews Dec. 2, 1947 2,810,027Woodward Oct. 15, 1957 2,831,075 Dumke Apr. 15, 1958 FOREIGN PATENTS366,607 Great Britain Feb. 11, 1932 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No, 2,968,704 January 11 1961 StewartA. Woodward et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 4, line 50, after "buttons" insert extending Signed and sealedthis 14th day of November 1961.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of PatentsUSCOMM-DC UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentNo. 2,968,704 January 17 1961 M Stewart A. Woodward et a1,

It is hereby certified that error appears in the above numbered patentrequiring correction and thatthe said Letters Patent should read ascorrected below,

Column 4, line 50, after "buttons" insert extending Signed and sealedthis 14th day of November 1961.

( SEAL) Attest:

ERNEST W. SW'IDER DAVID L. LADD Attesting Officer Commissioner ofPatents USCOMM-DC

